Window-latch



D. D. LEWIS.

wmoow LATCH. APPLICATION FILED OCT. 19, 1916.

1 28,284, Patented Jan. 20, 1920 l'l LUMM Judi/726M121. %M'Mm Gu ana/1,8

DAVID D. LEWIS, OF DETROIT, MICHIGAN.

WINDOW-LATCH.

Specification of Letters Patent.

Patented Jan. 20, 1920.

Application filed October 19, 1916. Serial No. 126,476.

To all whom it may concern:

Be it known that I, DAVID D. Lnwls, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in 'thindow-Latches, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to a window latch or catch whereby a sash is securely locked when down or is held at any desired elevation by a very simple and efficient and easily operated device.

The invention consists in the matters hereinafter set forth, and more particularly pointed out in the appended claims.

In the drawings,

Figure l is a view of a window sash on which a device that embodies the invention is mounted together with the window frame or casing and the locking strip secured thereon; and

Fig. 2 is a view, enlarged, partially in section and partially in plan, of a structure and retaining strip.

As herein indicated in preferred form. a corrugated strip 1 of sheet metal or the like is secured to the side of a window frame 2 in such relation to the sash or sash stop that movement of the sash causes the sash side to pass along parallel with and under the strip.

A base plate 2-2 is secured by suitable means such as screws 33. to the casing, and affords support for a pair of oppositely disposed dogs 3 and 4: which are pivoted on screw studs 5 and 6 so that the end por tions 7 and 8 of the pawls may'be brought into engagement with the corrugations of the strip 1.

A crescent shaped rock arm 9 of sheet metal has a pair of upturned ends 10 that abut against overlying lateral projections 11 and 12- of the pawls 5 and 6. A thumb piece 13 extends from the pivot center of the yoke outwardly beyond the base plate. A screw 14 acts as a pivot for the yoke through which it passes into engagement with the base plate 22.

Preferably the yoke is of sheet metal stamped to proper form and bent to provide the ears or lugs 10 while the finger piece is bent transversely upon itself to form a convenient thumb rest 15.

A crescent shaped spring 16 encircles the stud 14; with the arms thereof bearing against the margins of the dogs 7 and 8 in such manner as to force the ends thereof to engage the strip unless the manipulation of the yoke holds one of the pawls, as for example the pawl being out of engagement. A casing 17 of suitable design that is detachably secured on the base plate 2 houses the mechanism.

As will be understood, the positions of projections 11 and 12 in the path of travel of the projections 10 provide a construction similar to that of a lost motion structure, in that each arm or member 9 is capable of movement in one direction without affecting the position of the dog with which its projection 10 cooperates, the movement of the arm in the other direction, however, caucing the projection 10 to cooperate with the dog projection to rock LhQ dog on its pivot; the two effects are shown in connection with the positions of the two dogs in Fig. 2 of the drawings.

As will be understood, the normal positions of the parts have the ends of the dogs engaging in a corrugation of strip 1, the projections 10 of member 9 being in contact with projections 11 and 12, the do s being held in this position by reason of spring 16, and the projections being in contact by reason of the fact that projections 11 and 12 are movable with and form part of the dogs themselves. When, therefore, it is desired to move the sash in either direction the thumb piece 15 is shifted opposite to that in which it is desired to move the sash, thus providing the lost motion efiect on the arm which extends in the direction toward which the thumb piece is moved, while the dog in the other position is rocked through the action of the contacting projections, disengaging this latter dog from the corrugation and permitting the sash to be moved in the proper direction, the dog which remains in engagement simply riding over the corrugations which are passed in moving the sash. For instance, in Fig. 2, the parts are in position to move the sash in an upward direction, the lost motion action being present in connection with dog 3 while the positive movement is had in connection with dog 4. The parts will remain in this position as long as pressure is applied to the thumb piece 15; when this pressure is released, the spring tension provided by that portion of the spring 16 which contacts with dog at in Fig. 2, will force said dog toward its normal position, with the result that projection 12 will co-act with projection 10 and rock member 9 on its pivot to a normal position, it being understood, of

course, that when both projections 10 are in contact with the projections of the dogs, the tension of spring 16 will be substantially equalized on both dogs, so that memher 9 will be maintained in its normal position.

Obviously, changes in the details of construction may be made without departing from the spirit of my invention and I do not care to limit myself to any particular form or arrangement of parts.

What I claim is 1. In sash lock construction wherein the sash is normally held locked against movement in either direction and is shit'table in either direction at will, a stationary corrugated strip, a pair oi? spring supported dogs having independent pivots with the dogs extending in opposite directions from the pivots and each adapted to normally engage strip corrugations, and means for rendering either dog inactive at will, said means including a pivoted member having a pair of arms combinedly producing a crescent-shape element with each arm having a lateral projection, each dog having a projecting element extendin into the path of travel of the correspon ing arm projection, the respective pivot points and the dog and arm projections being relatively positioned to concurrently permit a lost motion relation with respect to the projection of one dog in the presence of member movement from its normal position to maintain engagement oat said dog with the strip mal position.

2. In sash lock construction, the combination with a corrugated strip adapted to be secured to a window casing adjacent the sash, of a base plate adapted to be secured to the sash adjacent the strip, a pair of pivot studs disposed on the base plate adjacent the corrugated strip, a pair of oppositely disposed dogs each pivoted on a stud and each having an end adapted to engage a recess of the strip, said dogs being oper ative to lock the sash against movement in the direction of extension of the dog, a yoke pivot stud secured on the base plate, said dog and yoke studs being relatively positioned at points corresponding to the apices of a triangle, a sheet metal crescent shaped yoke pivoted between its ends on the yoke stud, an operating arm extending from the yoke adjacent the yoke studs and having a thumb piece formed on the end portion thereof, lateral projections on each (flog, inturned end portions on the yoke and engaging the projections of the adjacent dog, and a crescent shaped spring secured on the yoke stud with the end portions thereof yieldingly forcing the dogs into engagement with the corrugated strip.

In testimony whereof I affix my signature in the presence of two witnesses.

DAVID D. LEWIS.

IVitnesses ANNA M. Donn, CHAS. W. Sraorrrenn. 

